Menisci are tough rubbery "C" shaped cartilage cushions that are attached by ligaments to the top (plateau) of the tibia. They prevent the surfaces of the tibia and femur from grinding against each other and act as the shock absorbers in the knee.
Meniscal tears are a common problem in the United States, menisci are also located in the shoulder, the most common meniscus injury occurs in the knee. There are two menisci in each knee. Each year, tens of thousands of people suffer meniscal tears, particularly in or at the site of one or both knees. If these tears are not repaired, there may be a progressive deterioration of the cartilage, leading to the painful rubbing and wearing of bones which had previously been covered by cartilage. This, in turn, leads to inflammatory synovitis, arthritis and other debilitating ailments. Consequently there are at least 30,000 to 40,000 meniscal excisions or repairs to the shoulder and the knee performed each year.
Men and women between the ages of 18 and 45 experience the majority of meniscal tears, usually during athletic activity, such as when twisting, cutting, pivoting, decelerating or when being tackled. When torn, the meniscus may have a longitudinal, horizontal, or radial ("parrot beak") tear.
The damaged meniscus may be diagnosed with the assistance or use of magnetic resonance imaging (MRI) and/or an arthroscopic examination. Arthroscopy enables a surgeon to look into the joint using a miniature video camera. In many cases, torn fragments of the meniscus are removed arthroscopically. In other cases, a small tear at the periphery of the meniscus with a very swollen knee joint may be treated by draining the joint, temporarily restricting the use of the knee, and slowly having the patient begin rehabilitative exercises.
However, in other cases, the tears in the meniscus do require surgical repair, normally by sewing the torn sections of the meniscus together. The use of the arthroscope greatly aids in the surgical repair of the meniscus by allowing the surgeon to better visualize the small areas between which the torn meniscus lies. The arthroscope enables the surgeon to visualize the interior of the joint and to perform surgery through small puncture holes without having to open the joint as has been done in the past.
A number of surgical tools have been developed to assist in suturing, and in particular the suturing of the meniscus.
U.S. Pat. No. 2,808,055 (Thayer) discloses a surgical stitching instrument which accommodates a bobbin of suture material and include means to feed the suture material to a needle. A slidable thread moving member is provided for advancing the suture material through the needle.
U.S. Pat. No. 3,476,114 (Shannon, et al.) discloses a ligating implement comprising an elongated instrument through which a ligature passes to form a loop at one end with a disc. The disc provides a means whereby the loop may be drawn tight above a severed vessel or the like.
U.S. Pat. No. 3,476,115 (Graeff, et al.) discloses a ligating implement as in Shannon, et al., and includes severing means to prevent overstressing of the locking disc during tightening of the noose.
U.S. Pat. No. 4,493,323 (Albright, et al.) discloses a suturing device and a method for its use in arthroscopic surgery. The suturing device comprises an elongated tube and plunger which are used to hold and advance a pair of needles united by a length of suture material.
U.S. Pat. No. 4,641,652 (Hutterer, et al.) discloses an applicator for tying sewing threads which comprises a helical tubular coil connected to a shaft having an axial passage. A catcher loop is extendable through the shaft to catch a sewing thread inserted manually into the coil passage.
U.S. Pat. No. 4,935,027 (Yoon) discloses surgical instruments and methods for affecting suturing of tissue controlled from a position remote from the suture site. The invention provides for the continuous feeding of suture material through opposed forcep jaw members between which the tissue segments are interposed.
U.S. Pat. No. 5,112,308 (Olsen, et al.) discloses a medical device for and a method of endoscopic surgery. The device includes a dilator having a tapered end and a central passage which accommodates a guide wire for directing the dilator. This device does not include any means whereby the guide wire may be secured to the dilator or otherwise manipulated in conjunction therewith.
U.S. Pat. No. 4,779,616 (Johnson) discloses a method for snagging an end of a surgical suture during arthroscopic surgery, comprising deploying a distal end of a cylindrical cannula adjacent to the end of the suture within the body and passing a resilient loop through the cannula to snag the suture.
U.S. Pat. Nos. 4,890,615, 4,923,461 and 4,957,498 (Caspari, et al.) disclose a suturing instrument and method of use in arthroscopic surgery. The suturing instrument includes a hollow needle for penetrating tissue to be sutured within the body while the tissue is clamped between relatively moveable jaws and a suture feed mechanism for feeding suture material through the hollow needle. The jaws can be opened and the suturing instrument withdrawn from the body, pulling the free end segment of the suture material with the instrument.